Re: Peculiar out-of-sync boot log lines

From: Sergei Shtylyov
Date: Fri Dec 07 2007 - 11:37:02 EST


Hello.

Bartlomiej Zolnierkiewicz wrote:

[PATCH] ide: DMA reporting and validity checking fixes (take 2)

* ide_xfer_verbose() fixups:
- beautify returned mode names
- fix PIO5 reporting
- make it return 'const char *'

* Change printk() level from KERN_DEBUG to KERN_INFO in ide_find_dma_mode().

* Add ide_id_dma_bug() helper based on ide_dma_verbose() to check for invalid
DMA info in identify block.

* Use ide_id_dma_bug() in ide_tune_dma() and ide_driveid_update().

As a result DMA won't be tuned or will be disabled after tuning if device
reports inconsistent info about enabled DMA mode (ide_dma_verbose() does the
same checks while the IDE device is probed by ide-{cd,disk} device driver).

* Since (id->capability & 1) && id->tDMA is a valid configuration handle
it correctly in ide_id_dma_bug().

Huh? You don't check (id->capability & 1) there...

* Remove no longer needed ide_dma_verbose().

This patch should fix the following problem with out-of-sync IDE messages
reported by Nick Warne:

hdd: ATAPI 48X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache<7>hdd:
skipping word 93 validity check
, UDMA(66)

and later debugged by Mark Lord to be caused by:

ide_dma_verbose()
printk( ... "2048kB Cache");
eighty_ninty_three()
printk(KERN_DEBUG "%s: skipping word 93 validity check\n");
ide_dma_verbose()
printk(", UDMA(66)"

Please note that as a result ide-{cd,disk} device drivers won't report the
DMA speed used but this is intended since now DMA mode being used is always
reported by IDE core code.

v2:
* fixes suggested by Randy:
- use KERN_CONT for printk()-s in ide-{cd,disk}.c
- don't remove argument name from ide_xfer_verbose() declaration

Cc: Nick Warne <nick@xxxxxxxxx>
Cc: Mark Lord <lkml@xxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>

[...]

Index: b/drivers/ide/ide-dma.c
===================================================================
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -806,58 +809,26 @@ static int ide_dma_check(ide_drive_t *dr
return vdma ? 0 : -1;
}
-void ide_dma_verbose(ide_drive_t *drive)
+int ide_id_dma_bug(ide_drive_t *drive)
{
- struct hd_driveid *id = drive->id;
- ide_hwif_t *hwif = HWIF(drive);
+ struct hd_driveid *id = drive->id;
if (id->field_valid & 4) {
if ((id->dma_ultra >> 8) && (id->dma_mword >> 8))
[...]
+ goto err_out;
} else if (id->field_valid & 2) {
if ((id->dma_mword >> 8) && (id->dma_1word >> 8))
- goto bug_dma_off;
- printk(", DMA");
+ goto err_out;
} else if (id->field_valid & 1) {

Hm, bit 0 only gurantees that current translation

- goto bug_dma_off;
+ if (id->tDMA == 0)

Despite the name, this is not a transfer period but SW DMA mode number, so why mode 0 is bad?

+ goto err_out;
}
- return;
-bug_dma_off:
- printk(", BUG DMA OFF");
- hwif->dma_off_quietly(drive);
- return;
+ return 0;
+err_out:
+ printk(KERN_ERR "%s: bad DMA info in identify block\n", drive->name);
+ return 1;
}
Index: b/drivers/ide/ide-lib.c
===================================================================
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -29,41 +29,44 @@
* Add common non I/O op stuff here. Make sure it has proper
* kernel-doc function headers or your patch will be rejected
*/
- +
+static const char *udma_str[] =
+ { "UDMA/16", "UDMA/25", "UDMA/33", "UDMA/44",
+ "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
+static const char *mwdma_str[] =
+ { "MWDMA0", "MWDMA1", "MWDMA2" };
+static const char *swdma_str[] =
+ { "SWDMA0", "SWDMA1", "SWDMA2" };
+static const char *pio_str[] =
+ { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" };
/**
* ide_xfer_verbose - return IDE mode names
- * @xfer_rate: rate to name
+ * @mode: transfer mode
*
* Returns a constant string giving the name of the mode
* requested.
*/
-char *ide_xfer_verbose (u8 xfer_rate)
+const char *ide_xfer_verbose(u8 mode)
{
[...]
+ const char *s;
+ u8 i = mode & 0xf;
+
+ if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
+ s = udma_str[i];
+ else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2)
+ s = mwdma_str[i];
+ else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
+ s = swdma_str[i];
+ else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5)
+ s = pio_str[i & 0x7];
+ else if (mode == XFER_PIO_SLOW)
+ s = "XFER SLOW";

Not "PIO SLOW"?

+ else
+ s = "XFER ERROR";
+
+ return s;
}

MBR, Sergei
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